/Engine/Source/Runtime/RenderCore/Public/VirtualTexturing.h
IAllocatedVirtualTexture ( const [FAllocatedVTDescription](API\Runtime\RenderCore\FAllocatedVTDescription) & InDesc, uint32 InBlockWidthInTiles, uint32 InBlockHeightInTiles, uint32 InWidthInBlocks, uint32 InHeightInBlocks, uint32 InDepthInTiles )